Joint general secretary Tony Woodley told The Telegraph: ‘‘It is not acceptable for trade unionists to act as strike-breakers in a legitimate industrial dispute, nor for pilots to use their privileged position to undermine much lower-paid trade union colleagues.

Jim McAuslan, Balpa general secretary, said: ‘‘Balpa and the vast majority of its members have a very different analysis of the situation in BA to representatives of the cabin crew union. We recognise the frustration that must have prompted so many cabin crew members to vote for strike action last year, but Balpa members were stunned by the threat of a 12-day strike at Christmas.

‘‘Balpa is not in dispute with BA and if and when a strike is called by the cabin crew union we will issue guidance to our members to ensure they comply with the law and operate normally to fulfil their full range of duties.

‘‘We understand a number of pilots have responded to BA’s call for volunteers to keep the airline operating through any strike and from their postings it is clear that this is out of concern for their own futures and that of other employees. For the avoidance of doubt, Balpa’s position on this is neutral and we will not dictate to our members.’’